Using scales as a speaker

I'm asked to speak on a regular basis to executives who are between employment opportunities. I start by asking them how they'll know that the next hour was a good use of their time. This is to get them thinking and contributing rather than sitting back being "motivated" as one said he wanted from my talk. I explained to him that I don't do motivation. To help them discover if the talk was a success, I ask them to scale where they are right now on a happiness or satisfaction scale from 1 to 10. I get them to write that number down. At the end of the hour, I bring them back to scaling and ask them to write down where they are now and to notice whether the number went up (or down) and then we discuss why. Then I suggest they can use this handy technique any time to determine whether life/work/love is improving or not.